Transformable Capillary Electrophoresis for Oligosaccharide Separations Using Phospholipid Additives

Phospholipids are used as an additive in capillary electrophoresis to enhance the separation of glycans derived from alpha1-acid glycoprotein, fetuin, and ribonuclease B. The properties of phospholipid preparations are dependent upon composition, hydration, and temperature. Separation performance is evaluated as a function of these variables. A preparation of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC), with [DMPC]/[DHPC] = 2.5, in 10% lipid/aqueous buffer at 25 degrees C provides the best separation efficiency at an electric field strength of 400 V/cm. Resolution is enhanced with the additive. Concanavalin A, a lectin selective for high mannose and mannose branching glycans, and alpha1-2,3 mannosidase, an enzyme that cleaves 1-2 and 1-3 mannopyranosyl residues, are incorporated in the separation to provide additional selectivity and to expand the application of phospholipid additives for glycan separation.